Definition - What does Retrial mean?
A retrial is when a brand new trial takes place, and the same plaintiff and the same defendant are debating the exact same issue after the original trial has already concluded.
Retrials are typically requested by the losing party. They only occur if the judge believes that there is good reason for a retrial, such as newly discovered evidence or a procedural error in the original trial.
Justipedia explains Retrial
If a retrial occurs due to newly discovered evidence, then the newly discovered evidence could potentially change the entire course of the trial. For example, if a murder weapon was never discovered before the original trial, but it was found afterward, causing a retrial, this could change everything. The murder weapon could bring forth DNA evidence or other important information that could help to determine the defendant's innocence or guilt.
Retrials exist to accommodate such changes of circumstances. However, they must be conducted in accordance with the law.